Malcolm John

Dr Malcolm John

Research Fellow

Organisation

University of Oxford

Research summary

Big questions require big machines. The Large Hadron Collider, which lies under the french countryside outside Geneva is certainly such an apparatus. Lying 100m underground and with a circumference of 27km, the LHC is built to study the highest energies that human technology can produce. Using thousands of powerful, super-conducting magnets, small samples of protons are whipped around in the ring at effectively, the speed of light. Each time they circulate [11,000 times a second], these sub-atomic particles intercept another bunch of protons traveling in the opposite direction. The two bunches largely pass through each-other unaffected but a couple of protons collide head-on, and do so at energies never before witnessed by mankind.

At such high energies the forces of nature are quite different from those that we experience in daily life. For a start, gravity has a completely negligible effect compared to the far stronger electromagnetic, weak and strong nuclear forces. Quantum mechanics dictates the behaviour of particles - the macroscopic approximations that feel intuitive to humans simply does not describe nature on very small scales. Nevertheless, the weird and wonderful zoo of particles that high-energy collisions produce are part of Nature and understanding their properties yields powerful insights into the big questions: what is mass? what is dark matter? where is all the anti-matter and why do we live in a three-dimensional space? Theorists can postulate many elegant solutions, but truth can only be identified via the unambiguous result of experiment.

The size of the experiments and their international reach has inspired both wonder and criticism over the last few years. But now that a long period of data-taking has begun, the results will flow and the benefit of this science will be witnessed by all. Mankind’s knowledge of the fundamental building blocks of Nature will take a big step forward this decade; the direction though, remains uncertain.